Fuel injection pump



July 27, 1943. H. m

FUEL INJECTION PUMP Filed June 7, 1941 Patented July 27, 1943 UNITED STATES PATENT OFFICE FUEL INJECTION PUMP Application June'7, 1941, Serial No. 396,994 In Germany April 16, 1940 Claims.

Now, according to this invention a simple and effective locking of the piston sleeve of injection pumps of the kind mentioned above against independent turning on the tappet is provided by causing the piston sleeve rotatably mounted in the pump casing to be pressed against the pump casing by the casing of the discharge valve with a pressure increased by spring action. In a par-- ticularly advantageous form, the springs producing the additional pressure are arranged in bores which for the purpose of adjusting the piston sleeve are provided in th surface of this sleeve facing the casing of the discharge valve.

It is also possible to use a single unit with one piston.-

In the accompanying drawing the preferred construction embodying the invention is shown by way of example.

Two or more bores 4 are provided at the face 3 of the piston sleeve I facing the casing 2 of the discharge valve. By employment of a suitable tool, these bores may be used to individually adjust the sleeve I. In the bores 4 coiled springs 5 are mounted which bear against the face 6 of the valve casing 2. After adjusting the piston sleeve I, the valve casing 2 may be pressed against the piston sleeve I by means of a cap nut, not shown in the drawing. The length-of the springs 5 is such that these springs are compressed by a height h when the valve casing 2 is pressed against them. The height of compression of the springs corresponds to the additionalpressure with which the piston sleeve l is to be pressed, by means of its shoulder I, against the pump casing 8. 9 designates the charging bore for the fuel, III an overflow bore, I I the pump casing, and I2 the cam for actuating the piston loaded by the'spring I3.

In this manner the pressure of the piston sleeve isso increased that the friction at the smooth faces 3, 6 is no longer suflicient to drive the piston sleeve I by friction when the valve case 2 is turned. Once the cap nut has been tightened, turning of the sleeve I is impossible.

Having now particularly described and ascertained the natur of my said invention and in what manner the same is to be performed I declare that what I claim is:

1. In a fluid pump, a pump housing enclosing a pump chamber, a hollow sleeve in said pump chamber, rotatably mounted in said housing and provided with one or more radial openings leading to the interior of said pump chamber, and a pump piston reciprocal within said sleeve, having a circumferentially variable controlling groove cooperating with at least one of said openings to control the flow of fluid to the interior of said pump chamber, whereby rotation of said sleeve in said housing will vary the relative position of said opening and controlling groove to vary the fluid flow to said pump chamber, one end of said sleeve being provided with a plurality of depressions adapted to-receive a tool for rotatably adjusting said sleeve, and means cooperating with said de pressed end of the sleeve to lock it against further rotation.

2. The combination according to claim 1, in which said depressions are formed as spring seats, in combination with springs in said seats, and a delivery valve casing movable in said housing in the direction of said sleeve, whose lower face is adapted to contact said springs, whereby when said delivery valve casing is pressed toward sleeve and held in contact with the end of the sleeve. said springs are compressed and serve as a lock to prevent rotation of said sleeve.

3. In a fluid pump, a pump housing enclosing a pump chamber provided with an internal annular shoulder, a hollow sleeve rotatable in said pump chamber having an annular abutment contacting said shoulder, said sleeve being provided with one or more openings leading to the interior of said pump chamber, a pump piston reciprocal within said sleeve, having a circumferentially variable controlling groove cooperating with at least one of said openings to control the flow of fluid to the interior of said pump chamber, whereby rotation of said sleeve in said housing will vary the relative position of said opening and controlling groove to vary the control of fluid to said pump chamber, and removable spring means for pressing the abutment on said sleeve against said shoulder to prevent relative rotation between said sleeve and pump housing.

4. The combination according to claim 3, in which said sleeve is provided with depressed spring seats in one end, and in which said spring means include springs in said seats, and means for pressing saidsprings into said seats.

5. The combination according to claim 3, in which said sleeve is provided with depressed springs in oneend, and in which said spring means include springs in said seats, and a delivery valve casing movable in said pump housing toward and away from the end of said sleeve for pressing said spring into said seats.

HEINZ LINKS. 

